I have no guarantee of absolute protection from zero-day threats, but no one does.
We can only do our best to keep up with current anti-virus and firewall rules, but protection of critical infrastructure is more than managing software updates. Some very common problems are often self-inflicted growing pains. Maintaining sufficient bandwidth and growing room is one of those things that still benefits from human assessment and guidance. A distributed denial of service (DDoS) attack will certainly impact your users and customers, but we can hurt ourselves just as badly if we don’t recognize our own limitations and bottlenecks. If we are not actively polling and monitoring the data consumption of our various elements – we have no baseline of expected performance.
I like to know what nominal behavior looks like, even at home.

Most network elements and servers provide SNMP protocol support for monitoring statistics and performance detail, but establishing an agent to help monitor and track this information can be an expensive process if you want a turn-key solution. There are plenty of high-end programs and appliances to provide graphs, alarms, and notifications – but that expense often gets deferred. A medium to large operation may be able to devote a full time person to manage projects utilizing NetBrain, CA_Spectrum, or HP_OpenView, but many don’t. Even minimal monitoring is better than none.
It is not that hard to give yourself a few simple and inexpensive tools.

screen shots from BigBrother, Cactii, & Nagios

The open-source world offers several tools in this arena, but these usually require some local talent to integrate and provide a product that can satisfy your requirements. Again, many operations hesitate to fund such a monitoring environment, or don’t feel justified in retaining such talent in-house. There is not a huge return on that investment, until something breaks.
Hey, it is working fine now, right..?

SomeNet.NET was registered on the internet in 1996, establishing a base for my research and consulting activities. Mostly it has my ham radio activities and some photography, as I have not so had much time available for consulting until recently. This type of network management and monitoring, is what I do. I even understand it, and know the value. I intend to be contributing a lot more on this blog in the near future, specifically on open-source tools and solutions that you might find useful.
I use these tools, even at home – and I AM an expert…